Census data from 1901-1971 on the status of Welsh in Wales are used to illustrate the problems of making language planning recommendations on the basis of limited and scale-specific analyses. Using maps and charts, the data are analysed at national, regional, local, and individual levels. Different patterns of language maintenance and usage emerge at each level for the same area. It is concluded that the various scales should be seen as complementary rather than alternative interpretations. The more ways of assessing the position of minority languages that are employed, the more realistic the approach to their conservation and development is likely to be. (EKN)